-2005 LGT with stock 32-bit ECU+modified tables
-version 9 EJ207 with EJ255 intake cams
-02-06 WRX Air Fuel/O2 sensor
This started happening randomly, though it's now more frequent, but at idle it would sometimes just turn off. Initially it would hesisitate and try to compensate(I'd say the pressure gauge losing vacuum), but still turned off. Today, it started happening while the clutch up and not necessarily at the stop light(happended again today while I was turning and also in a parking lot). Also, on a cold motor I can sometimes feel it hesitating under ~2000rpm and part throttle; so I assume it's related to something during closed loop.
I thought it may be a vacuum leak or something but I couldn't find any(I retorqued the BPV and clamps on the turbo hose to make sure).
I do have a CEL, P0131 IIRC; could that cause it? It's not the sensor itself since I replaced it and am getting the same code; I'm sure it's the ECU that can't read that range(rescaled the table to read that O2 sensor; 32bit ECU). I've ordered an OE O2 sensor but it's still in transit. Though, I've had that code for a while and it never ran this badly.
Please, any suggestions or where to look would help immensely.